Novel treatment technique

Transcription

1 Final conference Zagreb, 27 th April 2018 TREAT How to choose the optimal rehabilitation technique Novel treatment technique Stanislav Lenart Slovenian National Building and Civil Engineering Institute (ZAG) 1

2 Table of content (D4.1) 1. MAINTENANCE TECHNIQUES WITH MINIMAL INTERRUPTION OF TRAFFIC REHABILITATION TECHNIQUES FOR DETERIORATED RAIL STRUCTURES IMPROVEMENT OF DETERIORATED RAIL STRUCTURES BY THE INJECTION OF HIGH- PRESSURE EXPANSION POLYURETHANE RESINS (DEMO) 2. NOVEL CONSTRUCTION TECHNIQUES CONSTRUCTION TECHNIQUES FOR TRACKS AND EARTHWORKS Light-weight material CONSTRUCTION TECHNIQUES FOR TRANSITION ZONES GRS TRANSITION ZONE GRS BRIDGE ABUTMENT 3. ADVANCED FINITE ELEMENT ANALYSIS 2

3 Table of content 1. MAINTENANCE TECHNIQUES WITH MINIMAL INTERRUPTION OF TRAFFIC REHABILITATION TECHNIQUES FOR DETERIORATED RAIL STRUCTURES IMPROVEMENT OF DETERIORATED RAIL STRUCTURES BY THE INJECTION OF HIGH- PRESSURE EXPANSION POLYURETHANE RESINS (DEMO) 2. NOVEL CONSTRUCTION TECHNIQUES CONSTRUCTION TECHNIQUES FOR TRACKS AND EARTHWORKS Light-weight material CONSTRUCTION TECHNIQUES FOR TRANSITION ZONES GRS TRANSITION ZONE GRS BRIDGE ABUTMENT 3. ADVANCED FINITE ELEMENT ANALYSIS 3

4 Maintenance techniques with minimal interruption of traffic IMPROVEMENT OF DETERIORATED RAIL STRUCTURES BY THE INJECTION OF HIGH-PRESSURE EXPANSION POLYURETHANE RESINS injected into the subgrade soil under the injection pressure approximately 2 bar remediation of differential settlements, sink holes, cracks, bearing capacity improvements, etc. chemical reaction happens in very short time (from 2 s to 30 s) and enables reliable control of quantity of resin to be injected 4

5 Maintenance techniques with minimal interruption of traffic IMPROVEMENT OF DETERIORATED RAIL STRUCTURES BY THE INJECTION OF HIGH-PRESSURE EXPANSION POLYURETHANE RESINS 2 test sections in Slovenia: Dolgi most (bridge transition zone) Divača (open track) 5

6 Maintenance techniques with minimal interruption of traffic IMPROVEMENT OF DETERIORATED RAIL STRUCTURES BY THE INJECTION OF HIGH-PRESSURE EXPANSION POLYURETHANE RESINS test section Dolgi most (bridge transition zone) Track geometry and track stiffness measurements were performed before and after the intervention Track stiffness measurements Expansion of polyurethane resin causes the increase of confining pressure leading to the increased stiffness 6

7 Maintenance techniques with minimal interruption of traffic IMPROVEMENT OF DETERIORATED RAIL STRUCTURES BY THE INJECTION OF HIGH-PRESSURE EXPANSION POLYURETHANE RESINS test section Dolgi most (bridge transition zone) 7

8 Maintenance techniques with minimal interruption of traffic IMPROVEMENT OF DETERIORATED RAIL STRUCTURES BY THE INJECTION OF HIGH-PRESSURE EXPANSION POLYURETHANE RESINS test section Dolgi most (bridge transition zone) no significant improvement 8

9 Maintenance techniques with minimal interruption of traffic IMPROVEMENT OF DETERIORATED RAIL STRUCTURES BY THE INJECTION OF HIGH-PRESSURE EXPANSION POLYURETHANE RESINS test section Divača (open track) 9

10 Maintenance techniques with minimal interruption of traffic IMPROVEMENT OF DETERIORATED RAIL STRUCTURES BY THE INJECTION OF HIGH-PRESSURE EXPANSION POLYURETHANE RESINS test section Divača (open track) 10

11 Maintenance techniques with minimal interruption of traffic IMPROVEMENT OF DETERIORATED RAIL STRUCTURES BY THE INJECTION OF HIGH-PRESSURE EXPANSION POLYURETHANE RESINS test section Divača (open track) Track geometry and deflection measurements were performed before and after the intervention 11

12 Maintenance techniques with minimal interruption of traffic IMPROVEMENT OF DETERIORATED RAIL STRUCTURES BY THE INJECTION OF HIGH-PRESSURE EXPANSION POLYURETHANE RESINS solution for remediation of differential settlements and bearing capacity improvements on railway track under traffic chemical reaction between two components of polyurethane resin compacts and stiffens the surrounding soil short reaction time -> reliable control of injection the injection affects (increase) track stiffness in case of low poorly graded fill material (marginal fill material) with sinkholes, while it has no impact on the track stiffness when compacted well graded high quality granular material is used 12

13 Novel construction techniques CONSTRUCTION TECHNIQUES FOR TRACKS AND EARTHWORKS: Light-weight material CONSTRUCTION TECHNIQUES FOR TRANSITION ZONES GRS transition zone GRS bridge abutment 13

14 Novel construction techniques LIGHT-WEIGHT MATERIAL Use in case of low bearing capacity etc. Leca mm Leca 0-32 mm Glassopor 14

15 Novel construction techniques LIGHT-WEIGHT MATERIAL Vacuum triaxial testing at ZAG: Four different levels of vacuum (confinement). Large range and high accuracy of load (1N 100 kn) Very small strain levels (0.0001%). 15

16 80 cm Novel construction techniques LIGHT-WEIGHT MATERIAL B C Location of local strain tranducers: A B C D A D A1, A2, A7 B3 C4, C5 D6 Average local strain was calculated from two opposite measurements. p = partial vacuum (5, 20, 25 and 40 kpa) 16

17 Novel construction techniques LIGHT-WEIGHT MATERIAL Glassopor dry density 240 kg/m 3 17

18 Novel construction techniques LIGHT-WEIGHT MATERIAL Glassopor test results 18

19 Novel construction techniques LIGHT-WEIGHT MATERIAL Glassopor test results - secant modulus at various phases 19

20 Novel construction techniques LIGHT-WEIGHT MATERIAL Railway embankment constructed from light-weight material on poor ground, Karin Noren-Cosgriff & Amir M Kaynia (NGI) lightweight aggregate or foam glass are primarily used as stabilising measures to reduce the ground stresses, and for reduction of load and settlement on poor ground Material Grading (mm) Dry density (kg/m3) Lightweight aggregate Foam glass 10 50/ Blasted rock Formation Layer Min 0,6 m reinforcing layer Min 0,6 m cover layer Fiber membrane Light weight filling material 20

21 Construction techniques for transition zones GRS TRANSITION ZONE - Reconstruction of Buna Bridge (Croatia, FP7 project SmartRail) GRS BRIDGE ABUTMENT - The first GRS integral bridge with FHR facing in Europe (Pavlovski potok, Slovenia, 2015) 21

22 Construction techniques for transition zones GRS BRIDGE ABUTMENT Extensive lab testing to better understand deformation behaviour of GRS Bridge across the Pavlovski potok stream in the village of Žerovinci in north-eastern Slovenia a single-span simply-supported deck is placed, without structural integration, on top of the GRS, immediately behind the facings full-height rigid (FHR) facings cast on place to improve behaviour 22

23 Construction techniques for transition zones GRS BRIDGE ABUTMENT Lenart S., Kralj M., Medved S.P., Šuler J. (2016). Design and construction of the first GRS integrated bridge with FHR facings in Europe. Transportation geotechnics, vol. 8, Construction of the gravel foundation, before wrapping the foundation with geosynthetics Construction of the GRS abutments by placing gravel bags on the shoulder of each layer and compaction of the backfill 23

24 Construction techniques for transition zones GRS BRIDGE ABUTMENT stage-construction of retaining structure without the use of a temporary supporting system full height rigid (FHR) facings by means of cast-in-situ concrete B gabions bags C geosynthetic layers D backfill material 24

25 Construction techniques for transition zones GRS BRIDGE ABUTMENT Positive effect of reinforcement pre-stressing 25

26 Construction techniques for transition zones GRS BRIDGE ABUTMENT Significant decrease of concrete needed for GRS abutments in comparison to conventional steel-reinforced concrete abutments (67.7 % decrease) Much lower environmental impact compared to equivalent conventional bridge Fifer Bizjak, K and Lenart, S (2018). Life cycle assessment of a geosynthetic-reinforced soil bridge system a case study, Geotextiles & Geomembranes (accepted) 26

27 Conclusions different techniques were reviewed and their main characteristics were presented a strong need to avoid railway line closers and to conduct maintenance works with as less as possible traffic interruptions injection of expanding polyurethane resin into and beneath the railway track (demonstrated and tested) light-weight material characterized with laboratory tests the first GRS integrated bridge with FHR facings in Europe (presented and analysed) 27